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Utah Geological Survey Miscellaneous Publication 06-3DMGeologic Map of the Lower Escalante River Area,

Glen Canyon National Recreation Area,Eastern Kane County, Utah

Although this product represents the work of professional scientists, the Utah Department of Natural Resources, Utah Geological Survey, makes no warranty, expressed or implied, regarding its suitability for a particular use. The Utah Department of Natural Resources, Utah Geological Survey, shall not be liable under any circumstances for any direct, indirect, special, incidental, or consequential damages with respect to claims by users of this product.This geologic map and digital dataset were funded by the Utah Geological Survey and the National Park Service. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Government.

GIS digital cartography by: Buck Ehler and Darryl GreerBase from U.S.G.S. Navajo Mountain (1981) 30'x60' quadrangle

Projection: UTM Zone 12Units: Meters

Datum: NAD 1927Spheroid: Clarke 18664 0 4 8 12 Kilometers

2 0 2 4 6 8 10 Miles

SCALE 1:100,00011.530

205 mils

Utah Geological Survey, 1594 W. North Temple, P.O. Box 146100Salt Lake City, Utah 84114-6100ph: 801-537-3300: fax 801-537-3400geology.utah.gov

in cooperation with the National Park Service

Utah Geological Surveya division ofUtah Department of Natural Resourcesin cooperation with theNational Park Service

Index to U.S. Geological Survey 7.5' quadrangles

Location of this map, Glen Canyon NRA, southern Utah

GlenCanyon

NationalRecreation

Area

1 Billingsley, G.H., Huntoon, P.W., and Breed, W.J., 1987, Geologic map of Capitol Reef National Park and vicinity, Emery, Garfield, Kane, and Wayne Counties, Utah: Utah Geological and Mineral Survey Map 87, scale 1:62,500. Geographic Information System (GIS) database files: http://science.nature.nps.gov/nrdata/datastore.cfm?ID=39074; digital map image: http://geology.utah.gov/maps/geomap/parkmaps/pdf/M-87.pdf.2 Doelling, H.H. and Willis, G.C., 2006, Geologic map of the Smoky Mountain 30’x60’ quadrangle, Kane and San Juan Counties, Utah, and Coconino County, Arizona: Utah Geological Survey Map 213 and 213DM (digital GIS files), 2 plates, scale 1:100,000. (also see) Doelling, H.H., and Davis, F.D., 1989, The geology of Kane County, Utah, geology, mineral resources, geologic hazards: Utah Geological and Mineral Survey Bulletin 124 (also published separately as UGMS Map 121), 10 pl., scale 1:100,000, 192 p. 3 Doelling, H.H., and Willis, G.C., 1999, Interim geologic map of the Escalante and parts of the Loa and Hite Crossing 30'x60' quadrangles, Garfield and Kane Counties, Utah: Utah Geological Survey Open-File Report 368, 19 p., 2 plates, scale 1:100,000. 4 This map.5 Huntoon, P.W., Billingsley, G.H., Jr., and Breed, W.J., 1982, Geologic map of Canyonlands National Park and vicinity, Utah: Moab, Utah, Canyonlands Natural History Association, scale 1:62,500. GIS database files: http://science.nature.nps.gov/nrdata/datastore.cfm?ID=38974. (also see) Doelling, H.H., 2004, Geologic map of the La Sal 30'x60' quadrangle, San Juan County, Utah: Utah Geological Survey Map 205, 2 plates, scale 1:100,000. 6 Thaden, R.E., Trites, A.F., Jr., Finnell, T.L., and Willis, G.C., 2006, Geologic map of the White Canyon - Good Hope Bay area, Glen Canyon National Recreation Area, Utah: Utah Geological Survey Miscellaneous Publication XXXDM, scale 1:50,000. (Digitized and modified from U.S. Geological Survey Bulletin 1125, scale 1:48,000, published in 1964)7 Willis, G.C., 2004, Interim geologic map of the lower San Juan River area, eastern Glen Canyon National Recreation Area and vicinity, San Juan County, Utah: Utah Geological Survey Open-File Report 443DM (digital GIS files), scale 1:50,000. 8 Willis, G.C., 2006 in preparation, Interim geologic map of the Hite Crossing and Lower Dirty Devil River area, Glen Canyon National Recreation Area, Garfield and San Juan Counties, Utah: Utah Geological Survey Open-File Report, scale 1:50,000, CD-ROM.9 Willis, G.C., 2006 in preparation, Interim geologic maps of the Bullfrog, Halls Crossing, Halls Crossing NE, Ticaboo Mesa, and Knowles Canyon quadrangles, Glen Canyon National Recreation Area, Garfield and San Juan Counties, Utah: Utah Geological Survey Open-File Report, scale 1:24,000, CD-ROM.10 Willis, G.C., and Cragun, S., 2006 in preparation, Interim geologic map of the Glen Canyon Dam to Lees Ferry area, Glen Canyon National Recreation Area, Garfield and San Juan Counties, Utah: Utah Geological Survey Open-File Report, scale 1:50,000, CD-ROM.Area where Escalante Map overlaps Capitol Reef Map

[Printed and GIS database files available at: Utah Department of Natural Resources Map and Bookstore: web: geology.utah.gov; email: bookstore@utah.gov; phone: 1-888-UTAHMAPThis map is a plot of Geographic Information System (GIS) files created to visually represent the content of the GIS data files. It is not a published map and it contains many features that do not meet UGS cartographic standards, such as automatically generated labels that may overlap other labels and lines.

Printed and GIS geologic maps that cover Glen Canyon NRA at 1:100,000 or larger scale, and index to U.S. Geological

Survey 30'x60' quadrangles

Geologic Map of the Lower Escalante River Area,Glen Canyon National Recreation Area,

Eastern Kane County, Utahby

Hellmut H. Doelling and Grant C. Willis2007

- 1 -

Geologic Map of the Lower Escalante River Area, Glen Canyon National

Recreation Area, Eastern Kane County, Utah

by

Hellmut H. Doelling

and

Grant C. Willis

Scale 1:100,000

Utah Geological Survey

a division of the

Utah Department of Natural Resources

in cooperation with

National Park Service

2007

Utah Geological Survey Miscellaneous Publication 06-3DM

GIS digital cartography by: Darryl Greer and J. Buck Ehler

Utah Geological Survey, 1594 W. North Temple, PO Box 146100

Salt Lake City, Utah 84114-6100

ph: 801-537-3300; fax 801-537-3400

www.geology.utah.gov

- 2 -

NOTICES

Although this product represents the work of professional scientists, the Utah Department of

Natural Resources, Utah Geological Survey, makes no warranty, expressed or implied, regarding

its suitability for a particular use. The Utah Department of Natural Resources, Utah Geological

Survey, shall not be liable under any circumstances for any direct, indirect, special, incidental, or

consequential damages with respect to claims by users of this product.

This geologic map and digital data set were funded by the Utah Geological Survey and the

National Park Service. The views and conclusions contained in this document are those of the

authors and should not be interpreted as necessarily representing the official policies, either

expressed or implied, of the U.S. Government.

Persons or agencies using these data specifically agree not to misrepresent the data, nor to imply

that changes they made were approved by the Utah Geological Survey, and should indicate the

data source and any modifications they make on plots, digital copies, derivative products, and in

metadata.

For use at 1:100,000 scale only. The Utah Geological Survey (UGS) does not guarantee accuracy

or completeness of data.

- 3 -

DESCRIPTION OF MAP UNITS

Quaternary

Qa Alluvial Deposits (Holocene) – Small amounts of poorly to moderately sorted alluvial

gravel, sand, silt, and clay are present in the bottom of most drainages; however, because

canyons are narrow and deposits are small, none are mappable at this scale; these alluvial

deposits consist of poorly to moderately well sorted boulder to pebble gravel, sand, silt,

and clay deposited in small drainages; and locally include small debris-flow deposits,

eolian sand and silt, colluvium, rockfall debris, low-level alluvial terrace deposits, and

alluvial-fan deposits; includes deposits in active part of wash and up to about 20 feet (6

m) above wash floor; 0 to 20 feet (0-6 m) thick.

Qea Mixed eolian and alluvial deposits (Holocene to Middle? Pleistocene) – Moderately to

very well sorted sand, silt, with lesser clay, deposited by wind and locally reworked by

water; locally mixed with small angular to subrounded rock fragments, pebbles, and

cobbles deposited as sheetwash and ephemeral-wash alluvium; commonly capped by

thick calcic soil (caliche) that commonly forms a resistant bench; common on broad

stable surfaces where it partially covers the bedrock and includes residual lag of

underlying rock; similar in setting and composition to Qes deposits except evidence of

alluvial activity is more common and dune forms are less developed; much of the unit is

locally derived; locally covers or partially covers undifferentiated coarse alluvial gravel

and alluvial fan deposits; 0 to 15 meters (0-50 ft) thick.

Qes Eolian sand (Holocene to Middle? Pleistocene) – Well- to very well sorted, well-rounded

sand with minor silt, deposited by wind; forms poorly to well developed dunes, mounds,

and sheet-like deposits in depressions and on the lee side of slopes where protected from

erosion for long periods of time; locally slightly reworked by alluvial processes and

burrowing animals; mostly derived from and present on upper surface of Navajo and

Kayenta Formations; residual lag of underlying rock is common; locally has well-

developed calcic soil (caliche); 0 to 15 meters (0-50 ft) thick.

Qat Alluvial river terrace deposits (Middle to Lower Pleistocene) – Moderately to well-

sorted cobble to pebble gravel and sand with minor silt and clay; forms terrace remnants

on benches and slopes near the Colorado River; clasts were transported by the river from

sources in eastern Utah and western Colorado; includes reworked terrace deposits that

drape down slope from the original deposits; present up to about 200 m (600 ft) above the

modern river bed; mapped deposits (exposed above high lake level) probably about 0.5 to

1 million years old (Willis, 2004); terrace deposits are common at several levels between

the river channel and the Lake Powell high-water line and are exposed when the lake is

low; probably about 0 to 9 meters (0-30 ft) thick.

- 4 -

Qag Alluvial gravels, undifferentiated (Upper to Lower Pleistocene) – Poorly to moderately

well sorted, boulder- to clay-sized, alluvial stream-terrace and pediment-mantle deposits

preserved as remnants above present streams and washes; commonly dominated by gravel

to small boulder sediments; composition reflects local sources; commonly includes eolian

silt and sand and calcic soil that gradually accumulates in upper part of deposits such that

older deposits have thicker accumulations; in general, older deposits are preserved at

higher levels above nearby streams and washes, but various levels have not been

differentiated; mostly Quaternary in age but age of highest-level deposits is poorly

constrained; 0 to 18 meters (0-60 ft) thick.

Qmst Mass-movement landslides, slumps, and talus, undifferentiated (Holocene to

Pleistocene) – Includes rock-fall deposits, colluvium, talus, toreva blocks, landslides,

slumps, and landslide complexes; very poorly sorted, chaotic deposits range in

composition from silt to large blocks several tens of meters in average diameter; upper

surfaces are typically hummocky; most landslides and slumps are inactive but some show

evidence of historical movement or reactivation near incised washes and along lake

shorelines; primarily forms in weaker rock units of the Cretaceous Straight Cliffs

Formation (forms cliffs and ledges of Kaiparowits Plateau just west of map border) and

Tropic Shale near Fiftymile Point, and in the core of the Circle Cliffs anticline near The

Rincon where rockfall debris is sliding on Chinle strata; in this area lake water and wave

action have saturated and weakened Chinle strata and previously existing landslides,

creating unstable slopes that are slumping into the lake, causing safety hazards (Grundvig,

1980); map unit locally includes alluvial, colluvial, and eolian deposits; highly variable

from 0 to 75 meters (0-250 ft) thick.

Cretaceous

Kt Tropic Shale (Upper Cretaceous, upper Cenomanian to middle Turonian) – Medium-

gray, yellow-gray, and olive-gray, fossiliferous, marine mudstone and shale with

subordinate gray fine- to very fine-grained sandstone, bentonitic claystone, siltstone, and

limestone in the upper and lower parts of the formation; forms badlands slopes; 150 to

230 meters (500-750 ft) thick to west (Doelling, 2006), but only lower about 60 meters

(200 ft) preserved in map area.

Kd Dakota Formation (Upper Cretaceous, Cenomanian, with possible upper Lower

Cretaceous, Barremian to Albian) – Interbedded gray-orange to light-brown sandstone,

sandy mudstone and shale, carbonaceous mudstone, shaley sandstone, conglomerate, and

dark-brown to black carbonaceous shale and coal; upper part is sandstone with marine

fossils; middle part is ledge- and slope-forming sandstone, mudstone, and coal-bearing

unit; lower part is a discontinuous local basal conglomerate that fills paleotopographic

lows and may be at least partly Early Cretaceous in age; forms ledges and slopes;

deposited in coastal plain, shoreline, near-shore marine, and lagoonal environments;

deposited unconformably across Morrison Formation (and older formations to west of

map area [Doelling, 2006]); thickness varies significantly across short distances;

- 5 -

regionally is 1 to 45 meters (3-150 ft) thick; within map area is about 14 to 17 meters (45-

55 ft) thick.

Jurassic

Jm Morrison Formation (Upper Jurassic) – Yellow-gray, gray, and yellow-brown, ledge-

and cliff-forming, lenticular conglomerate, conglomeratic sandstone, and sandstone,

interbedded with subordinate green-gray to purple-gray, to dark red-brown, smectitic

(swelling clay) mudstone; cut out just west of map area due to unconformity at base of

Dakota Formation that cuts increasingly down-section to the west; outcrops in map area

are primarily Salt Wash Member but thin, slope-forming Brushy Basin Member may be

present above the Salt Wash, and a thin interval of Tidwell Member may be present

below the Salt Wash; deposited in fluvial-lacustrine environment unconformably across

underlying Middle Jurassic units; 170 to 210 meters (550-680 ft) thick (Peterson and

Barnum, 1973).

Jr Romana Sandstone (Middle Jurassic) – Gray-yellow, green-gray, yellow-gray, and

light-tan, very fine- to fine-grained, medium-bedded to massive, planar to cross-bedded,

calcareous sandstone with thin planar beds of reddish-brown, calcareous, sandy siltstone;

forms massive to ledgy cliff; deposited in shallow marine, tidal flat, and eolian

environments; 0 to 45 meters (0-145 ft) thick regionally; about 12 to 40 meters thick (40-

130 ft) in map area.

Je Entrada Sandstone (Middle Jurassic) – Mostly well-sorted, well-rounded, fine-grained

sandstone; consists of two members (not differentiated on map) based on differences in

bedding, weathering characteristics, and color; the lower (Gunsight Butte Member) is

orange-brown and weathers into smooth, rounded, "slickrim" erosional forms and cliffs;

the upper (Cannonville Member) is red-brown, commonly banded, and forms a blocky

cliff; an overlying third member (Escalante Member) is not preserved in the map area but

is present to the northwest (Doelling and Willis, 2006); 220 to 240 meters (720-780 ft)

thick (Peterson and Barnum, 1973).

Jc Carmel Formation (Middle Jurassic) – Combined Paria River and Winsor Members of

the Carmel Formation; upper part (Winsor Member) is mostly medium- to dark-red-

brown to yellow-brown, slope-forming, earthy-weathering, silty sandstone and siltstone

intercalated with sporadic irregular beds of white, calcareous, fine-grained sandstone that

is locally gypsiferous; lower part (Paria River Member) is mostly dark-red-brown

siltstone and silty sandstone with a few tan to brown, fine-grained sandstone beds capped

by white to pale-red-gray, silty to sandy, chippy-weathering limestone; conformable and

interfingers with Page Sandstone; deposited in shallow marine, sahbka, and tidal flat

environment along southeast side of inland sea; 33 to 52 meters (110-170 ft) thick; upper

part (Winsor) is 18 to 45 meters (60-150 ft) thick, lower part (Paria River) is 15 to 20

meters (50-65 ft) thick.

- 6 -

Jp Page Sandstone (Middle Jurassic) – Mostly pale-yellow-orange, to red-orange, fine- to

medium-grained, cross-bedded, quartzose sandstone, locally with thin, dark-red siltstone

and silty sandstone beds; unconformably overlies the similar-appearing Navajo

Sandstone; in map area consists of three undifferentiated eolian cross-bedded sandstone

tongues, the Harris Wash (lower), Thousand Pockets (middle), and Leche-e (upper)

(Blakey and others, 1996); to the west and northwest the Judd Hollow Tongue of the

Carmel Formation is between the Harris Wash and Thousand Pockets (Doelling and

Willis, 2006) but in this map area the Judd Hollow is very thin to missing and is not

mappable; 10 to 75 meters (30-250 ft) thick.

Jn Navajo Sandstone (Lower Jurassic) – Pale-yellow-gray, orange-gray, pale-red-brown,

brown, and very pale-gray, massive, cross-bedded to locally convolute-bedded, fine- to

medium-grained sandstone that forms prominent cliffs, domes and bare-rock outcrops;

characterized by massive eolian cross-bed sets; lower part has planar beds that grade

upward into cross-beds; has local limestone and dolomite lenses (interdunal playa or lake

deposits); 290 to 425 meters (950-1400 ft) thick.

Jk Kayenta Formation (Lower Jurassic) – Ledge- and slope-forming, lenticular sandstone,

siltstone, and mudstone with local limestone and intraformational conglomerate beds;

mostly medium- to dark-red-brown, but red-orange, red-purple, white, and brown

sandstone is common; deposited in alluvial floodplain to lacustrine environments;

conformable with units above and below; 58 to 104 meters (190-340 ft) thick.

Jurassic – Triassic

JTRw Wingate Sandstone (Lower Jurassic to Upper Triassic) – Pale- to medium-red-orange to

red-brown, massive, cliff-forming, fine- to medium-grained, cross-bedded sandstone;

forms “walls” of broad, blocky, strongly jointed, smooth sandstone cliffs and bluffs; 60 to

90 meters (200-300 ft) thick.

Triassic

TRcu Upper members of the Chinle Formation (Upper Triassic) (includes Church Rock, Owl

Rock, and Petrified Forest Members) – Individual members are recognizable in the field,

but are impractical to map separately at this scale; overall, unit forms a slope to ledgy

slope that steepens upward to ledgy cliffs just below the massive Wingate Sandstone cliff.

Approximately 70 meters (230 ft) of this combined map unit consisting primarily of

Church Rock and Owl Rock Members is poorly exposed along the lower walls of

Escalante Canyon and tributaries where it forms a low slope with scattered ledges and is

commonly covered by talus; these members, and the Petrified Forest Member, are also

present but most covered or incorporated in landslide debris in the core of the Circle

Cliffs anticline at The Rincon. The Church Rock Member consists of interbedded red-

brown to pale-red-brown siltstone and fine- to medium-grained, micaceous sandstone

with abundant ripple laminations, mudcracks, and small-scale cross-beds; lenticular

- 7 -

pebble and rip-up clast conglomerate beds are locally present near base; the Church Rock

is similar in color to the overlying Wingate and forms a steep ledgy slope commonly

draped with Wingate rock-fall debris. The Owl Rock Member consists of pale-green-

gray, pale-purple-gray, and pale-red-gray, calcareous sandstone, mottled limestone, and

siltstone; calcrete pedogenic paleosols (fossil soils) are abundant. The Petrified Forest

Member consists of vibrant purple-red, red-gray, and green-gray, slope-forming, smectitic

(swelling clay) mudstone and thin beds of fine- to coarse-grained sandstone.

Subsurface Units – shown on cross section only

TRc Chinle Formation, undivided (Upper Triassic) ( includes members described above,

plus possible Mossback, Monitor Butte, and Shinarump Conglomerate Members)

TRm Moenkopi Formation (Lower Triassic)

P Permian strata

IP Pennsylvanian strata

M Mississippian strata

D Devonian strata

C Cambrian strata

pC Precambrian rock

- 8 -

SOURCES AND REFERENCES

This map was compiled primarily from the 1:100,000-scale geologic map of Kane County (Doelling and Davis,

1989; and sources listed therein). The authors made significant modifications in 2005.

Blakey, R.C., Havholm, K.G., and Jones, L.S., 1996, Stratigraphic analysis of eolian interactions

with marine and fluvial deposits, Middle Jurassic Page Sandstone and Carmel Formation,

Colorado Plateau, U.S.A.: Journal of Sedimentary Research, v. 66, no. 2, p. 324-342.

Doelling, H.H., and Davis, F.D., 1989, The geology of Kane County, Utah, geology, mineral

resources, geologic hazards: Utah Geological and Mineral Survey Bulletin 124 (also

published separately as UGMS Map 121), 10 pl., scale 1:100,000, 192 p.

Doelling, H.H., and Willis, G.C., 2006, Geologic map of the Smoky Mountain 30’x60’

quadrangle, Kane and San Juan Counties, Utah, and Coconino County, Arizona: Utah

Geological Survey Map 359, 2 plates, scale 1:100,000.

Grundvig, D., 1980, Landslide surveillance of Lake Powell: U.S. Bureau of Reclamation, Region

4 Division of Design and Construction, Geology Branch, Geology Report G-321,

unpaginated.

Peterson, F. and Barnum, B.E., 1973, Geologic map and coal resources of the northeast quarter of

the Cummings Mesa [Navajo Point] quadrangle, Kane County, Utah: U.S. Geological

Survey Coal Investigations Map C-63, 2 pl., scale 1:24,000.

Willis, G.C., 2006, Interim geologic map of the lower San Juan River area, eastern Glen Canyon

National Recreation Area and vicinity, San Juan County, Utah: Utah Geological Survey

Open-File Report 443DM, scale 1:50,000, CD-ROM.